DPVBi유도체에 의한 유기청색발광소자의 광학적 특성 평가

오환술,오세용 건국대학교 산업기술연구원 2003 건국기술연구논문지 Vol.28 No.-

To stabilize white OLEDs with the operating voltage by two wavelengths methods, we synthesized the novel blue emitting material based on methyl & methoxy substituted DPVBi materials. Two types of light emitting devices were processed, which type I was ITO/TPD/methyl-DPVBi/Al and type Ⅱ was ITO/TPD/methoxy- DPVBi/Al structure. The PL peak wavelengths of two devices were 483㎚, 506㎚ respectively. And they were shifted to the longer wavelength compared to DPVBi(450㎚) due to electron donation effects. The peak EL emission wavelength of devices were 468㎚, 535㎚ respectively at 15 Volt.

MOCVD법에 의한 광 통신용 1.55㎛ PBH-DFB 레이저 다이오드 제작

오환술,김중연,전현성,강명구 건국대학교 산업기술연구원 1997 건국기술연구논문지 Vol.22 No.-

DC-PBHDFB LD operating at 1.55㎛ were fabricated by 3-step MOCVD process. The first-order grating with 2370Å period and 700Å etching depth was formed by holographic lithography and wet etching. Fabricated DCPBH-DFB LD operates in single longitudinal mode with side-mode suppression of more than 35dB and the lasing wavelength of 1.547㎛ at room temperature and 5mW, and the lasing threshold current and the slope efficiency were 15.6mA and 0.15mW/mA, respectively. The characteristic temperature of threshold current(To) and the temperature dependence of the lasing wavelength were obtained 57.3K and 1.0Å/℃ from the DFB laser between 20℃ and 70℃, respectively.

GaAlAs/GaAs DHLD의 結晶成長과 光電特性

吳煥述 건국대학교 1982 學術誌 Vol.26 No.2

The properties of Al0.3Ga0.7As/GaAs double heterostructure Laser diode operating by at wavelengths in the 0.847㎛ by Liquid phase epitaxy(LPE) grown layer are described. This device exhibit good electrical and optical confinement. The theoretical liquid and solid phase diagram for the LPE of AlGaAs ternary alloys has been described based on the thermodynamic equilibrium condition. The growth rates of GaAs and Al0.3Ga0.7As are ∼1㎛/℃, ∼0.5㎛/℃ respectively. The threshold current density increases with temperature for diode made from material near the band gap crossover composition. And the peak energy of the emission spectra measured on grown Al0.3Ga0.7As/GaAs LD are found to be 1.46eV(8470℃) and 1.83eV(6770Å) in the case EL (Electro Luminescent) and PL (Photo Luminescent) at 77˚K. For sufficiently narrow active layers, emission is usually single longitudinal mode oscillation and linear. CW light output power up to∼10 mW per facet have been observed at 77˚K.

ZnO 薄膜의 製造 및 電氣的 特性에 관한 硏究

吳煥述 건국대학교 부설 산업기술연구소 1980 논문집 Vol.6 No.-

Zno thin film semiconductor was processed by vacuum deposition technique. Their electrical properties and sensitivity to various gases characteristics were investigated. The change in conductivity of ZnO thin film devices when contacted with gases was considered as the change in carrier concentration caused by adsorption effect. Also the conductivity change of the element was caused by the change of atmosphere pressure around them.

적색형광색소 첨가에 의한 유기발광소자의 전기적 및 광학적 특성분석

오환술 건국대학교 산업기술연구원 2001 건국기술연구논문지 Vol.26 No.-

Red emission organic electroluminescent devices was fabricated by fluorescence dyes(DCM1 and Nile Red) doping into the Alq3 upon the ITO which was coated on glass. Two types of device were employed which type I was ITO/TPD/Alq3:DCMl/Al and type II was ITO/TPD/Alq3:Nile Red/Al structure. The dye concentration was variable 15~60 wt% for type I and 10~50wt% for type II. The peak omission wavelength of device I, II, III of type I was respectively 605nm, 611nm, 623nm. and turn-on voltage were 2~4V and driving voltage were 6V. The peak emission wavelength of device I, II, III of type II was respectively 621nm, 626nm, 637nm. Device I, II of type II had a driving voltage 6~8V but device III, IV had more than 11V. We obtained higher efficiency and natural red emission from type II than type I due to energy transfer mechanism. Finally we obtained emission luminescence 110 cd/m2 at 11V with device II of type II.

디지털 파이버 光通信系統에서의 直接 光檢波의 最適化에 관한 硏究

金暎權,吳煥述 건국대학교 1981 學術誌 Vol.25 No.1

Our study is concerted about theoretical optimization of direct detection of the digital data signal that are transmitted over the fiber optic communication systems. Direct detection is provided by a photodetector whose output-current is modeled as a noisy filtered poison stream of pulse. In this model, the timevarying pulse arrival rate is proportional to a linearly distorted version of the modulating signal. When the average energy in the response of the photodetector to an individual photon is small compared to the additive thermal noise, the optimum detector is shown to be linear except for the use of precomputed bias terms. At the other extreme are the photomultiplier and the avalanche photodiode where the average energy in the response of the photodetector to a signal photon is large compared with the additive noise. For PAM signaling, we demonstrate that finite system memory allows application of dynamic programming to provide a detector implementation whose computational complexity dose not increase with time.

MOS 구조에서의 얇은 산화막에 대한 절연특성에 관한 연구

엄금용,오환술 건국대학교 1997 學術誌 Vol.41 No.2

Tungsten polycide has studded gate oxide reliability and dielectric strength charactristics as the composition of gate electrode. The gate oxide reliability has been tested using the TDDB (Time dependent dielectric breakdown) and SCTDDB (stepped current TDDB) and interface trapped characteristics has been tested using C-V plot. It was confirmed that tungsten polycide layer is a better reliabily properities than polysilicon layer. Also, hole trap is detected on the polysilicon structure on the other hand electron trap is detected on polycide structure. In the case of electron trap, the WSi₂ layer is larger interface trap generation than polysilicon on large pocl3 doping time and high pocl₃ doping temperature condition. Breakdown characteristics of than dielectric is the most high quality at 850℃ 30min, 900℃ 20min on polycide structure in the meanwhile A, B mode (allure is the most small at the same condition. Also flatband voltage shift is slowly increase with larger pocl₃ doping time.

金屬薄膜導波管을 利用한 I/O Mode Filter

박한규,오한솔,김명수 연세대학교 산업기술연구소 1981 논문집 Vol.13 No.2

代表的인 3종류의 金屬薄膜導波管의 TEo-Mode와 TMo-Mode의 특성을 Computer Simulation에 의하여 비교 고찰하였다. 非對稱型平板薄膜導波管으로된 금속박막도파관은 TEo-Mode Filtering이 不可能하였다. 對稱型平板薄膜導波管으로된 금속박막도파관에서는 Film층과 그 외의 층과 굴절율 차이가 0.02 이하가 되면 TEo-Mode Filtering이 가능하며 TMo-Mode 의 損失이 10dB/cm이하가 되어 Mode Filter로서 使用可能함이 밝혀졌다. The typical three kinds of the Metal-Clad waveguides have been chosen, and the characteristics of TEo-Mode and TMo-Mode in them are investigated and compared with each other by computer simulation. TEo-Mode filtering has been impossible in the Metal-Clad waveguide made of the symmetric thin film slab waveguide. In the Metal-Clad waveguide made of the symmetric thin film slab waveguide, if the refraction index difference between the film layer and the other layers is below 0.02, it has made TEo-Mode filtering possible and has had TMo-Mode loss below 10dB/㎝. Therefore it has been improved that it can be used practically as a Mode Filter.

ARRAY MODE CHARACTERISTICS OF CHANNELED-SUBSTRATE-PLANAR PHASE ARRAYS

hwan sool Oh,J.K. Butler 대한전자공학회 1986 대한전자공학회 학술대회 Vol.1986 No.6

An Analysis of Two Coupled Slab Waveguides Fabricated with Vanadium Oxide and Lithium Niobate (1)

Oh, Hwan Sool 건국대학교 1986 學術誌 Vol.30 No.2

In this paper I discuss the analysis and numerical computations relating to the coupling of optical modes between two neighboring waveguides. The waveguides are fabricated with Lithium Niobate as guide 1 and Vanadium Oxide as guide 2. In a waveguide system that incorporates two lossless guides, a complete transfer of polder from one guide to another can occur when the waveguides are (1) identical or (2) the modes in each guide hove identical phase constants. Here I discuss the coupling effects when the guides are dissimilar with respect to both geometry and losses. In these results, I show that power transfer can occur between the two guides, one lossy and the other lossless, provided the phase matched condition is satisfied When properly coupled, the power attenuation varies according to the amount of coupling.